how to make multiple website on one host

["jeffry s" <paragasu@xxxxxxxxx>]

i am wondering whether this can be done. i know it can.
is it possible to make one website with the ability to host multiple
website.
it is something like website generator. eg: www.shopify.org

let say for example i have a website www.example.org.
i can point a domain name (www.example1.org) to the server where
www.example.org hosted,
and when user visit www.example1.org, it execute the same scripts as
www.example.org with
with different themes and website configuration.

anyone have the idea?

thanks